JP6823830B2 - Lighting device - Google Patents

Description

The present invention relates to a lighting device that illuminates a predetermined range using coherent light.

A laser light source has a longer life than a high-pressure mercury lamp, an optical system can be miniaturized, and power consumption is low. Therefore, a lighting device using a laser light source is becoming widespread.

For example, Patent Document 1 discloses a vehicle lamp that can use a laser oscillator as a light source. This vehicle lamp is provided with a hologram element, and the hologram element is recorded with a hologram pattern calculated so that the diffracted light reproduced by irradiating the reference light forms a light distribution pattern with a predetermined luminous intensity distribution. Will be done.

Japanese Unexamined Patent Publication No. 2012-146621

By using an optical element such as a hologram element in combination with a laser light source as described above, it is possible to irradiate a desired region with coherent light typified by laser light. The above-mentioned lighting device using coherent light can be applied to devices in various fields, and can be suitably applied to, for example, vehicle headlights.

On the other hand, there is a desire to subdivide the illumination area into a large number of element illumination areas to illuminate the illumination area more precisely, or to illuminate a part or the whole of the illumination area by the element illumination areas arranged at a higher density. There is. However, in a system in which a hologram element and a laser light source are combined, in general, as the number of element illumination regions increases, the number of hologram elements increases and the configuration becomes large. Therefore, a system capable of safely irradiating coherent light to a densely arranged element illumination region by an illumination device having a configuration that does not depend on the number of light diffusing elements such as a hologram is preferable.

The laser light source capable of emitting coherent light is a lamp light source or an LED (Light).
Compared to the Emitting Diode), it can emit laser light with strong energy in a small light emitting area, and has the advantage that the light distribution can be finely controlled and the light can be delivered to a long distance. However, coherent light from a laser light source having a very small product (etandu) of light emitting area (cross-sectional area of luminous flux) and emission angle (solid angle) has a possibility that the light power density becomes locally large. When applying such coherent light to lighting devices such as vehicle headlights that may be directly viewed by humans, it is necessary to ensure safety.

The present invention has been made in view of the above circumstances, and an object of the present invention is to realize a lighting device capable of safely illuminating a desired area by using coherent light with a simple configuration.

One aspect of the present invention is a coherent light source that emits coherent light, a light diffusing element that diffuses coherent light from the coherent light source, and an optical scanning device that scans coherent light from the light diffusing element in an illumination region. The present invention relates to an illuminating device including an optical scanning device for guiding coherent light to an element illuminating area constituting a part of the area.

According to this aspect, it is possible to safely illuminate a desired element illumination area using coherent light by an illuminating device having a simple configuration.

The lighting device may include a controller that controls the timing of incident light of coherent light on the light diffusing element or the timing of lighting in the lighting region.

The lighting device may include a timing control unit that controls the emission timing of the coherent light according to the scanning of the coherent light by the optical scanning device.

The optical scanning device includes an irradiation surface portion that is irradiated with coherent light from a light diffusing element to change the optical path of the coherent light, and a scanning drive unit that adjusts the arrangement of the irradiation surface portion, and the coherent light is diffused by the light diffusing element. The angle may be smaller than the angle of the element illumination region with respect to the irradiation surface portion.

According to this aspect, the "diffusion angle of coherent light by the light diffusing element" is defined to be included in an appropriate range according to the "angle of the element illumination region with respect to the irradiation surface portion".

The diffusion angle of coherent light by the light diffusing element may be greater than 0.05 ° and less than 2 °.

According to this aspect, it is possible to appropriately illuminate an element illumination region having a spread while suppressing the diffusion of coherent light by the light diffusing element to an appropriate range. Therefore, it is possible to omit the installation of the optical element for reducing the diffusion angle of the coherent light increased by the light diffusion element, and the lighting device can be configured simply and compactly.

The angle of the element illumination region with respect to the irradiation surface portion of the optical scanning device may be larger than 0.1 ° and smaller than 5 °.

According to this aspect, it is possible to appropriately irradiate the element illumination region with coherent light whose diffusion is suppressed to an appropriate range by a light diffusing element.

The optical scanning device may be arranged at a position based on the imaging position of the coherent light from the light diffusing element.

The optical scanning device may be arranged at a position corresponding to the imaging position of the coherent light from the light diffusing element, or may be arranged in the vicinity of the imaging position. When the optical scanning device is arranged at a position corresponding to the imaging position of the coherent light from the light diffusing element, it can be considered that the light diffusing element is virtually arranged at the position of the optical scanning device.

The light diffusing element may be a hologram.

The light diffusing element may be a microlens array.

According to this aspect, it is easy to suppress the diffusion of coherent light in the light diffusing element to an appropriate range.

The illuminating device further includes a relay optical system arranged between the light diffusing element and the optical scanning device, and the coherent light from the light diffusing element may be guided to the optical scanning device via the relay optical system.

According to this aspect, the arrangement position of the optical scanning device and the irradiation area of coherent light can be controlled by the relay optical system, and the above-mentioned lighting device can be flexibly applied to various types of optical scanning devices.

The illuminator may further include a beam expander that is located between the coherent light source and the light diffusing element to increase the diameter of the coherent light from the coherent light source.

According to this aspect, the beam expander can optimize the incoming area of coherent light for the light diffusing element.

The illuminator may further include a collimating optical system that is arranged between the beam expander and the light diffusing element to parallelize the coherent light from the beam expander.

According to this aspect, the diffusion of coherent light by the light diffusing element can be easily suppressed to an appropriate range.

A plurality of coherent light sources that emit coherent light having different wavelengths are provided, and a plurality of light diffusing elements are provided so as to correspond to each of the plurality of coherent light sources, and diffuse the coherent light from the corresponding coherent light sources. A plurality of light diffusing elements are provided, and the lighting device may further include an optical guide unit that guides coherent light having different wavelengths from the plurality of light diffusing elements to the optical scanning device.

The optical guide unit is composed of a first optical guide body installed between a light diffusing element of one of a plurality of light diffusing elements and an optical scanning device, and another light diffusing element of the plurality of light diffusing elements. The first optical guide body includes a second optical guide body that guides the coherent light of the above to the first optical guide body, and the first optical guide body lightly scans the coherent light from one light diffusing element and the coherent light from another light diffusing element. You may lead to the device.

A plurality of coherent light sources that emit coherent light having different wavelengths from each other are provided, and the illuminating device may further include an optical guide unit that guides coherent light having different wavelengths from the plurality of coherent light sources to the light diffusing element. Good.

The optical guide unit provides coherent light from a first optical guide body installed between a coherent light source of one of a plurality of coherent light sources and a light diffusing element and another coherent light source of the plurality of coherent light sources. The first optical guide body may guide the coherent light from one coherent light source and the coherent light from another coherent light source to the light diffusing element, including a second optical guide body that guides the first optical guide body. ..

The lighting device is a plurality of collimating optical systems provided so as to correspond to each of the plurality of coherent light sources, and further includes a plurality of collimating optical systems for parallelizing the coherent light from the corresponding coherent light sources, and an optical guide unit. May guide coherent light, which is emitted from a plurality of coherent light sources and has different wavelengths after passing through a plurality of collimating optical systems, to a light diffusing element.

The illuminator further comprises a collimating optical system that parallelizes coherent light having different wavelengths, and the optical guide unit directs coherent light having different wavelengths from a plurality of coherent light sources toward the collimating optical system. It may be emitted and guided to the light diffusing element.

The illuminator further comprises a beam expander that expands the diameter of the coherent light, and the optical guide unit emits coherent light from multiple coherent light sources with different wavelengths through the beam expander and collimating optics. It may be guided to a diffuser element.

Another aspect of the present invention includes a coherent light source that emits coherent light, an optical scanning device that changes the traveling direction of the coherent light from the coherent light source, and a light diffusing element that diffuses the coherent light from the optical scanning device. The optical scanning device relates to a lighting device that scans coherent light that has passed through a light diffusing element in an illuminating region and guides the coherent light to an element illuminating region that constitutes a part of the illuminating region.

The coherent light whose traveling direction is changed by the optical scanning device contains light components having different wavelengths from each other, and a spectroscopic unit is provided between the optical scanning device and the light diffusing element, and the coherent light from the optical scanning device is provided. The light enters the light diffusing element via the spectroscopic unit, and the spectroscopic unit disperses the coherent light from the optical scanning device and separates the coherent light into a plurality of light components having different wavelengths, and separates the plurality of light components into a plurality of light components having different wavelengths. It may be emitted toward the light diffusing element.

The spectroscopic unit transmits the light component in the first wavelength range and guides it to the light diffusing element, and also reflects the light component in the other wavelength range in the first spectroscopic guide body and the other reflected by the first spectroscopic guide body. A second spectroscopic guide body that guides the light component in the wavelength range of the above to the light diffusing element may be included.

According to the present invention, the lighting device can be simply configured. In addition, coherent light can be used to safely illuminate a desired area.

FIG. 1 is a conceptual diagram showing a schematic configuration of a lighting device according to a first embodiment of the present invention. FIG. 2 is a block diagram showing an example of a functional configuration of the controller. FIG. 3 is a conceptual diagram for explaining an illumination region of laser light guided by an optical scanning device. FIG. 4 is a conceptual diagram showing a schematic configuration of the lighting device according to the first modification. FIG. 5 is a diagram showing an arrangement example of the folded mirror and the irradiation surface portion (optical scanning device) in the modified example shown in FIG. 4, and shows a configuration example in which the laser beam is folded back in the vertical direction by the folded mirror. FIG. 6 is a diagram showing an arrangement example of the folded mirror and the irradiation surface portion (optical scanning device) in the modified example shown in FIG. 4, and is a configuration example in which the laser beam is folded back in the left-right direction (side direction) by the folded mirror. Shown. FIG. 7 is a conceptual diagram showing a schematic configuration of the lighting device according to the second modification. FIG. 8 is a conceptual diagram showing a schematic configuration of the lighting device according to the third modification. FIG. 9 is a conceptual diagram showing a schematic configuration of a lighting device according to a second embodiment of the present invention. FIG. 10 is a conceptual diagram showing a schematic configuration of a lighting device according to a third embodiment of the present invention. FIG. 11 is a conceptual diagram showing a schematic configuration of a lighting device according to a fourth embodiment of the present invention. FIG. 12 is a conceptual diagram showing a schematic configuration of a lighting device according to a fifth embodiment of the present invention. FIG. 13 is a conceptual diagram showing a schematic configuration of a lighting device according to a sixth embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings attached to the present specification, the scale, aspect ratio, etc. are appropriately changed from those of the actual product and exaggerated for the convenience of illustration and comprehension.

In addition, as used in this specification, the terms such as "parallel", "orthogonal", and "same" and the values of length and angle, etc., which specify the shape and geometric conditions and their degrees, are strictly defined. Without being bound by meaning, we will interpret it including the range in which similar functions can be expected.

[First Embodiment]
FIG. 1 is a conceptual diagram showing a schematic configuration of a lighting device 1 according to a first embodiment of the present invention.

In the lighting device 1 according to the present embodiment, the laser light source 11, the beam expander 12, the collimating optical system 13, the light diffusing element 14, the relay optical system 18, and the optical scanning device 21 are sequentially arranged.

The laser light source 11 is a light source that emits laser light, that is, coherent light L, and a semiconductor laser light source can typically be used as the laser light source 11. The number of light sources constituting the laser light source 11 may be singular or plural. When the laser light source 11 is composed of a plurality of light sources, the wavelength ranges of the laser light L emitted from the plurality of light sources may be the same as each other or may be different from each other. In order to increase the emission intensity of the laser light L emitted from the laser light source 11, it is preferable that the wavelength ranges of the laser light L emitted from the plurality of light sources overlap. When the wavelength ranges of the laser light L emitted from the plurality of light sources constituting the laser light source 11 are different, the plurality of light sources may be provided independently of each other, or may be arranged on a common substrate to form a light source module. May be formed. For example, when a plurality of light sources constituting the laser light source 11 can emit laser light L in a red wavelength region, a green wavelength region, and a blue wavelength region, by superimposing these three types of laser light L, a white laser light L can be emitted. It is also possible to generate illumination light.

The laser light source 11 may include a light emission control unit (not shown) that controls the light emission of the laser light. The light emission control unit is controlled by a light emission timing control unit 25 described later. For example, the emission control unit may individually and independently control the emission timing of a plurality of laser beams having different emission wavelength ranges. That is, when a plurality of light sources are provided corresponding to a plurality of laser lights having different emission wavelength ranges, the emission control unit can control the emission timing for emitting the laser light from the plurality of light sources for each light source. .. Therefore, when the laser light source 11 can emit three laser beams of red, green, and blue, by controlling the emission timing of each laser beam, the illumination light of any color of red, green, and blue or any two colors of red, green, and blue can be emitted. It is possible to generate illumination light of a color that is a mixture of the above colors. Further, the light emission control unit may control the light emission intensity of the laser light in each light source, and can also emit a laser light having a strong light emission intensity or a laser light having a weak light emission intensity from each light source.

The beam expander 12 is arranged between the laser light source 11 and the light diffusing element 14, in this example, between the laser light source 11 and the collimating optical system 13, and expands the diameter of the laser light L from the laser light source 11. Further, the collimating optical system 13 is arranged between the beam expander 12 and the light diffusing element 14, and parallelizes (colimates) the light from the beam expander 12. In this way, the laser beam L having a small diameter emitted from the laser light source 11 is expanded in diameter by the beam expander 12 and the collimating optical system 13 to be adjusted to parallel light, and the light diffusing element 14 provided in the subsequent stage is inserted. It is optimized for the size of the light portion and is incident on the light diffusing element 14. In addition, in order to facilitate the illustration and understanding, the illustration of the laser beam L in the collimating optical system 13 to the optical scanning device 21 is omitted in FIG.

The light diffusing element 14 is composed of a set of a plurality of unit diffusing elements 15 and diffuses the laser light L from the laser light source 11. As will be described later, in the present embodiment, the light diffusing element 14 is preferably an optical element having high directivity capable of diffusing the laser beam L at a relatively gentle angle. Such a light diffusing element 14 can typically be configured by a microlens array, and each unit diffusing element 15 can be configured by individual microlenses that make up the microlens array. Further, the light diffusing element 14 may use a hologram recording medium. Specifically, examples of the hologram recording medium include a computer synthetic hologram (CGH: Computer Generated Hologram) and a Fourier transform hologram. Further, the hologram recording medium may be a volumetric hologram recording medium using a photopolymer, a volumetric hologram recording medium of a type recording using a photosensitive medium containing a silver salt material, or a relief type (embossed type). ) Hologram recording medium may be used.

The detailed configuration and operation of the light diffusing element 14 will be described later.

The relay optical system 18 is arranged between the light diffusing element 14 and the optical scanning device 21, and includes the first relay lens 16 and the second relay lens 17 in the present embodiment. The laser light L from the light diffusing element 14 is guided to the optical scanning device 21 via the relay optical system 18, and is imaged on the irradiation surface portion 19 of the optical scanning device 21. Therefore, in the present embodiment, an image corresponding to the light diffusing element 14, that is, a virtual microlens array 31, is formed on the irradiation surface portion 19 of the light scanning device 21. It is also possible to treat such a virtual microlens array 31 formed on the irradiation surface portion 19 of the optical scanning device 21 as a virtual light source, and the laser light L from the virtual microlens array 31 is shown in FIG. As shown, it may be considered that the element illumination region 41 constituting the illumination region 40 is irradiated.

The specific configuration of the relay optical system 18 is not particularly limited, but by adjusting the optical performance of the optical element group constituting the relay optical system 18, that is, the focal distances of the first relay lens 16 and the second relay lens 17. The relay optical system 18 can function as a 1x magnification optical system, a magnifying optical system, or a reducing optical system. For example, by configuring the relay optical system 18 with two lenses having the same focal length, the first relay lens 16 and the second relay lens 17, the optical magnification of the relay optical system 18 can be made equal (1x). It is also possible to do. On the other hand, by forming the relay optical system 18 with two lenses having different focal lengths, the first relay lens 16 and the second relay lens 17, the optical magnification (enlargement or reduction) according to the ratio of the focal lengths of the lenses. It is also possible to have the relay optical system 18. As described above, by using the relay optical system 18 as the afocal relay optical system, both sides are telecentric, and the image height on the injection side can be made constant. As a result, the influence of the irradiation area on the light diffusing element 14 is extremely small in the illumination region in the far field of view, so that very high-definition illumination can be performed. When the relay optical system 18 constitutes the reduction optical system, the diffusion angle of the laser beam L from the optical scanning device 21 is relatively large, and when the relay optical system 18 constitutes the magnifying optical system, the diffusion angle is relatively large. The diffusion angle of the laser beam L from the optical scanning device 21 is relatively small.

In the present embodiment, as will be described later, the element illumination region 41 constituting the illumination region 40 is illuminated by the laser beam L by irradiating the irradiation surface portion 19 of the optical scanning device 21 with the laser beam L from the light diffusing element 14. To. Therefore, by adjusting the "irradiation range (irradiation area) of the irradiation surface portion 19 of the optical scanning device 21" of the laser beam L from the light diffusing element 14 by the relay optical system 18, an appropriate range (area) on the irradiation surface portion 19 is adjusted. ) Is irradiated with the laser beam L.

The optical scanning device 21 includes an irradiation surface portion 19 on which the laser beam L from the light diffusing element 14 is irradiated, and a scanning drive unit 20 that adjusts the arrangement of the irradiation surface portion 19. As shown in FIG. 3, the laser light L from the light diffusing element 14 is scanned in the illumination region 40, and the laser light L is guided to the element illumination region 41 which constitutes a part of the illumination region. That is, the irradiation surface portion 19 changes the optical path of the irradiated laser light L to guide the laser light L to the element illumination region 41 constituting the illumination region 40. The scanning drive unit 20 is connected to the controller 22, and under the control of the controller 22, the element illumination area 41 in the illumination area 40 irradiated by the laser beam L can be changed by adjusting the direction of the irradiation surface unit 19. The irradiation surface portion 19 is typically composed of a mirror, for example, a MEMS (Micro Electro Electrical Systems) mirror such as a polygon mirror, a two-axis galvano mirror, a resonance mirror, or a large reflecting surface having a diameter of several tens of millimeters (mm). Examples thereof include a caliber type two-axis resonance mirror.

Further, as described above, in addition to the optical scanning device having a mirror, a member such as a lens that transmits laser light may be vibrated to scan the laser light. Specific examples include a Fresnel lens. The laser beam incident on the Fresnel lens passes through the Fresnel lens and scans the inside of the irradiation region. In the case of an optical scanning device using a Fresnel lens, the emission surface of the laser beam can be the irradiation surface portion 19.

The optical scanning device 21, particularly the irradiation surface portion 19, is arranged at a position based on the imaging position of the laser beam L from the light diffusing element 14. In the present embodiment, as described above, the laser light L emitted from the unit diffusion element 15 of the light diffusion element 14 is irradiated to the irradiation surface portion 19 of the optical scanning device 21 via the relay optical system 18. Therefore, in the present embodiment, the optical scanning device 21 is based on the imaging position determined according to the optical performance (focal length) of each unit diffusion element 15 of the light diffusion element 14 and the optical performance (focal length) of the relay optical system 18. The placement position of is determined. When the relay optical system 18 is not provided, the irradiation surface portion 19 of the optical scanning device 21 is based on the imaging position determined according to the optical performance (focal length) of each unit diffusion element 15 of the light diffusion element 14. It is preferable to determine the arrangement position of.

The "position based on the imaging position of the laser beam L from the light diffusing element 14" here typically refers to a position that coincides with the imaging position, but does not necessarily coincide exactly with the imaging position. You don't have to be. The irradiation surface portion 19 of the optical scanning device 21 may be arranged in a range in which the influence on the imaging performance can be tolerated, for example, in the vicinity of the “imaging position of the laser beam L from the light diffusing element 14”.

The controller 22 is connected to the laser light source 11 and the optical scanning device 21, particularly the scanning driving unit 20 of the optical scanning device 21, and controls the on-off of the light emission of the laser light L from the laser light source 11 and the irradiation surface portion of the optical scanning device 21. The scanning of the laser beam L by 19 is controlled. Whether or not to make the laser light source 11 emit light is determined by providing an optical shutter unit (not shown) between the laser light source 11 and the light diffusing element 14 in addition to the on-off control of the light emission of the laser light source 11. , The passage / blocking of the laser beam may be switched by this optical shutter unit. Therefore, the controller 22 controls the incident timing of the laser light on the light diffusing element 14 or the illumination timing of the illumination region.

FIG. 2 is a block diagram showing a functional configuration example of the controller 22. The controller 22 of this example includes a light emission timing control unit 25 that controls the laser light source 11, and an optical scanning control unit 26 that controls the scanning drive unit 20 of the optical scanning device 21.

In particular, the light emission timing control unit 25 of the present embodiment cooperates with the optical scanning control unit 26 to control the light emission timing of the laser light L according to the scanning of the laser light L by the optical scanning device 21. As a result, as shown in FIG. 3, only a part of the illumination region 40 can be selectively illuminated by the laser beam L or not illuminated.

FIG. 3 is a conceptual diagram for explaining the illumination region 40 of the laser beam L guided by the optical scanning device 21.

In the present embodiment, the element illumination region 41 forming a part of the illumination region 40 is illuminated by the laser light L guided by the optical scanning device 21. That is, instantaneously, only a single element illumination region 41 of the illumination region 40 is illuminated by the laser light L from the optical scanning device 21. When illuminating the entire area of the illumination area 40, the laser beam L is scanned at high speed in the illumination area 40 by the optical scanning device 21. The scanning method of the laser beam L by the optical scanning device 21 is not particularly limited, and may be a raster scanning method, a Lissajous scanning method, or a vector scanning method, as shown by reference numeral “S” in FIG. May be good.

The division method of each element lighting area 41 in the lighting area 40 is not particularly limited. The range that can be instantaneously illuminated by the laser beam L from the optical scanning device 21 is defined as the element illumination region 41. Therefore, each element illumination region 41 is determined according to the emission timing of the laser light L from the laser light source 11 controlled by the controller 22 and the scanning position of the laser light L by the optical scanning device 21. Therefore, for example, as shown in FIG. 3, each element illumination area 41 may be set so that the element illumination areas 41 do not overlap each other, or each element illumination may be set so that the element illumination areas 41 overlap each other. Regions 41 may be set, or elemental illumination regions 41 that overlap each other and element illumination regions 41 that do not overlap each other may be mixed in the illumination region 40.

In this way, the element illumination region 41 illuminated by the laser beam L from the optical scanning device 21 gradually expands greatly as the distance from the optical scanning device 21 increases, depending on the diffusion angle of the laser beam L. Therefore, each element illumination region 41 constituting the illumination region illuminated by the illumination device 1 is a region wider in a position (far field) relatively far from the optical scanning device 21 than in a position relatively close (near field). It becomes. Therefore, it is often more convenient to express the size of the element illumination area by the angular distribution in the angular space than to express it by the actual dimensions of the element illumination area. The term "illuminated area" in the present specification may include the angular range of the illuminated area in the angular space in addition to the actual irradiated area and illuminated range by the laser beam L.

Next, the detailed configuration and operation of the light diffusing element 14 shown in FIG. 1 will be described.

With respect to the laser light L diffused by the light diffusing element 14 and emitted from the light diffusing element 14, each of the unit diffusing elements 15 constituting the light diffusing element 14 serves as a virtual light source. That is, the laser light L emitted from the light diffusing element 14 can be considered as the laser light L emitted from a plurality of virtual light sources.

Generally, if the irradiation intensity of the laser light L required in the illumination region (elemental illumination region) is the same, the laser light L emitted from a plurality of light sources is more than the laser light L emitted from a single point light source. The light power density can be lowered and the safety is high. That is, if the irradiation intensity of the entire laser light L is the same, the laser light L emitted from a plurality of light sources is directly viewed by the human eye rather than the laser light L emitted from a single point light source is directly viewed by the human eye. In the case, the degree of adverse effect on the human eye when the light source image is formed on the retina is smaller. Therefore, by providing a light diffusing element 14 including a plurality of unit diffusing elements 15 in the subsequent stage of the laser light source 11 as in the present embodiment, an element that constitutes an illumination region using the laser light L that has passed through the light diffusing element 14. The illumination area 41 can be safely illuminated.

It should be noted that the law of Etendue generally holds as a characteristic of light in an optical system. This etandu stipulates that the product of the cross-sectional area of the luminous flux (emission area) and the solid angle of the diffused light (radiation angle) is stored at a constant value, and what kind of spread the area and angle of the light have. Shown. When the light diffusing element 14 is arranged on the optical path of the laser light L as in the present embodiment, the Etandu's law is based on the light diffusing element 14 with respect to the downstream side of the light diffusing element 14 in the traveling direction of the laser light L. It can be considered with reference to the formed "apparent light source".

The diffusion angle of the laser beam L by the light diffusing element 14 is smaller than the angular space range of the element illumination region 41, that is, the angle of the element illumination region 41 with respect to the irradiation surface portion 19 of the optical scanning device 21.

As described above, it is preferable that the area of the light source is large for safety, but in order to promote the densification of the element illumination region 41 in the illumination using the laser light L emitted from the large light source area, the light flux of the laser light L is cut off. It is necessary to reduce the area. However, under Etandu's law, if the cross-sectional area of the light flux of the laser beam L is reduced, the diffusion angle of the laser beam L becomes large, and it becomes difficult to illuminate a wide range with an appropriate light intensity. That is, as the diffusion angle of the laser beam L becomes larger, the optical mechanism for adjusting the diffusion angle of the laser beam L required to illuminate the element illumination region 41 in a limited range tends to become enormous and complicated. is there. Further, with respect to the traveling direction of the laser light L guided by the optical scanning device 21, the diffusion angle of the laser light L by the light diffusing element 14 forming the apparent light source is small in order to illuminate a wide range with an appropriate light intensity. Is preferable. Therefore, in order to illuminate the element illumination region 41 in a limited range of a certain size over a wide range with an appropriate light intensity, the diffusion angle of the laser beam L by the light diffusing element 14 may be included in an appropriate angle range. Preferably, such an appropriate angular range is determined according to the angular range of the element illumination region 41.

Specifically, the diffusion angle of the laser beam L by the light diffusion element 14 is preferably larger than 0.05 ° and smaller than 2 °. Here, the "diffusion angle of the laser light L by the light diffusing element 14 of the present embodiment" is determined by the diffusion angle of the laser light L by the individual unit diffusing elements 15 constituting the light diffusing element 14, and each unit diffusing element 15 Preferably has a diffusion angle greater than 0.05 ° and less than 2 °. Further, the angle of the optical scanning device 21 with respect to the irradiation surface portion 19 of each element illumination region 41 is preferably larger than 0.1 ° and smaller than 5 °. When these ranges include the diffusion angle of the laser beam L by the light diffusing element 14 and the angular range of the element illumination region 41, the element illumination region 41 can be illuminated over a wide range with an appropriate light intensity.

The "diffusion angle of the laser light L by the light diffusing element 14" is a value measured by irradiating the light diffusing element 14 with the laser light L, and the parallel light laser light L is diffused by the light diffusing element 14. It is represented by the angle. Further, the "angle of the element illumination region 41 with respect to the irradiation surface portion 19 of the optical scanning device 21 (angle range of the element illumination region 41)" is the representative position of the irradiation surface portion 19 of the optical scanning device 21 and the element illumination region 41. An angle formed by a line connecting the representative positions, for example, an angle formed by a plurality of lines connecting one or more representative positions on the irradiation surface portion 19 and two or more representative positions of the element illumination region 41. It can be expressed.

As described above, according to the illumination device 1 of the present embodiment, the laser light is transmitted through the light diffusion element 14 having a light diffusion angle in a predetermined range and the scan light scanning device 21 for scanning the laser light L in the illumination region 40. The element illumination region 41 is illuminated by L. As a result, it is possible to realize the illuminating device 1 capable of safely illuminating the element illuminating region 41 in the illuminating region 40 using the laser beam L. Further, it is possible to obtain a lighting device having a simple structure without using a complicated and expensive device.

<First modification>
FIG. 4 is a conceptual diagram showing a schematic configuration of the lighting device 1 according to the first modification of the lighting device 1 shown in FIG. In this modification, a folded mirror 45 is provided between the second relay lens 17 of the relay optical system 18 and particularly the irradiation surface portion 19 of the optical scanning device 21. Other configurations are the same as those of the above-mentioned lighting device 1 shown in FIG.

The folded mirror 45 reflects the laser light L from the second relay lens 17 of the relay optical system 18 and guides the reflected laser light L to the irradiation surface portion 19 of the optical scanning device 21 in particular. By using the folded mirror 45, the traveling direction of the laser beam L can be changed to a desired direction, and the course of the laser beam L can be flexibly optimized according to the space requirement such as the installation space. Therefore, as compared with the case where the optical axis of the laser beam L is bent at a relatively large angle such as a right angle by the irradiation surface portion 19 of the optical scanning device 21 as in the illumination device 1 shown in FIG. 1, the folded mirror 45 is as in this modification. It is possible to arrange the optical system more compactly when the laser beam L is appropriately adjusted by using.

The specific configuration of the folding mirror 45 is not particularly limited, and the folding mirror 45 may be configured by a plane mirror, the folding mirror 45 may be configured by a concave mirror, and the folding mirror 45 is provided as a part of the relay optical system 18. May be done. Further, the folding direction of the laser beam L by the folding mirror 45 is not particularly limited.

5 and 6 are views showing an arrangement example of the folded mirror 45 and the irradiation surface portion 19 of the optical scanning device 21 in the modified example shown in FIG. 4, and are folded from the front direction (see the arrow “X” in FIG. 4). It is the figure which looked at the mirror 45 and the irradiation surface part 19. FIG. 5 shows a configuration example in which the laser beam L is folded back in the vertical direction by the folding mirror 45, and FIG. 6 shows a configuration example in the case where the laser beam L is folded back in the left-right direction (side direction) by the folding mirror 45. As described above, the direction in which the laser beam L is folded back by the folding mirror 45 is not particularly limited, and the folding mirror 45 can guide the laser beam L in a desired direction. Further, a plurality of folding mirrors 45 may be provided, and a plurality of folding mirrors 45 capable of folding back the laser beam L in different directions are provided as a second relay lens 17 of the relay optical system 18 and an irradiation surface portion 19 of the optical scanning device 21. It may be provided between and.

<Second modification>
FIG. 7 is a conceptual diagram showing a schematic configuration of the lighting device 1 according to the second modification of the lighting device 1 shown in FIG. In this modification, instead of the beam expander 12, an optical fiber 48 is provided between the laser light source 11 and the collimating optical system 13. Other configurations are the same as those of the above-mentioned lighting device 1 shown in FIG.

In this example, the laser beam L emitted from the laser light source 11 travels directly into the optical fiber 48 from the laser light source 11, and the laser beam L is emitted from the optical fiber 48 toward the collimating optical system 13. The laser beam L emitted from the optical fiber 48 is incident on the collimating optical system 13 in the state of diffused light, and is parallelized (colimated) by the collimating optical system 13.

In this configuration, the larger the beam diameter of the laser light L after collimation by the collimating optical system 13 with respect to the core diameter of the optical fiber 48 (the diameter of the traveling path of the laser light L), the more highly parallel the laser light L becomes. It can be converted and the parallelism of light rays can be increased.

<Third modification example>
FIG. 8 is a conceptual diagram showing a schematic configuration of the lighting device 1 according to the third modification of the lighting device 1 shown in FIG. In this modification, a plurality of laser light sources 11 are provided, and a plurality of collimating optical systems 13 are provided. Further, instead of the beam expander 12, a plurality of optical fibers 48 are provided between each laser light source 11 and each collimating optical system 13. Other configurations are the same as those of the above-mentioned lighting device 1 shown in FIG.

In this example, a unique optical fiber 48 and a unique collimating optical system 13 are assigned to each laser light source 11, and the laser light L emitted from each laser light source 11 is assigned to each of the assigned optical fibers 48. The laser light L travels directly from the laser light source 11, and then the laser light L is emitted from the optical fiber 48 toward the assigned collimating optical system 13. In this modification as well, as in the second modification described above, the laser beam L emitted from each optical fiber 48 is incident on each collimating optical system 13 in the state of diffused light and parallelized by each collimating optical system 13. (Collected).

By emitting the laser light L emitted from the plurality of laser light sources 11 through the plurality of optical fibers 48 as in this example, it is possible to reduce the core diameter of each optical fiber 48 if the total output is constant. is there. Therefore, the angular variation of each laser beam L that has passed through the collimated optical system 13 (collimated optical system array), that is, each laser beam L after collimation is reduced, and the laser beam L that is closer to parallel light is transmitted to each collimated optical system 13. Can be emitted from.

[Second Embodiment]
FIG. 9 is a conceptual diagram showing a schematic configuration of the lighting device 1 according to the second embodiment of the present invention. In the present embodiment, the same or similar elements as those in the above-described first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. In addition, in order to facilitate illustration and understanding, the illustration of the laser beam L in the collimating optical systems 13a, 13b, 13c to the optical scanning device 21 is omitted in FIG.

In the present embodiment, the first laser light source 11a, the second laser light source 11b, and the third laser light source 11c are provided as a plurality of laser light sources. The first laser light source 11a, the second laser light source 11b, and the third laser light source 11c each emit laser light L having different wavelengths from each other.

As a plurality of light diffusing elements, a first light diffusing element 14a, a second light diffusing element 14b, and a third light diffusing element 14c are provided. The first light diffusing element 14a, the second light diffusing element 14b, and the third light diffusing element 14c are composed of holograms so as to correspond to the first laser light source 11a, the second laser light source 11b, and the third laser light source 11c, respectively. It is provided in the above and diffuses the laser light L from the corresponding laser light source.

Further, the illumination device 1 is the laser light L from the first light diffusing element 14a, the second light diffusing element 14b, and the third light diffusing element 14c, and the laser light L having different wavelengths is transmitted to the light scanning device 21. An optical guide unit 50 for guiding is further provided. The optical guide unit 50 includes a first optical guide body 51 and a second optical guide body 52.

The first optical guide body 51 is installed between one of the plurality of light diffusing elements 14a to 14c, the first light diffusing element 14a in FIG. 9, and the optical scanning device 21, and is dichroic. Has a mirror. The first optical guide body 51 having a dichroic mirror is also called a dichroic cube, and has a property of transmitting the laser light L from the first light diffusing element 14a while reflecting the laser light L having another wavelength. On the other hand, the second optical guide body 52 is derived from the other light diffusing elements 14a to 14c among the plurality of light diffusing elements 14a to 14c described above, and in FIG. 9, each of the second light diffusing element 14b and the third light diffusing element 14c. It has a mirror that guides the laser beam L to the first optical guide body 51. The first optical guide body 51 travels from each of the laser light L from the first light diffusing element 14a, the second light diffusing element 14b, and the third light diffusing element 14c via the second optical guide body 52. The laser light L is guided to the optical scanning device 21 via the relay optical system 18.

A plurality of beam expanders and collimating optical systems are also provided. That is, a first beam expander 12a and a first collimating optical system 13a are provided between the first laser light source 11a and the first light diffusing element 14a, and between the second laser light source 11b and the second light diffusing element 14b. Is provided with a second beam expander 12b and a second collimating optical system 13b, and a third beam expander 12c and a third collimating optical system 13c are provided between the third laser light source 11c and the third light diffusing element 14c. It is provided. The plurality of collimating optical systems 13a to 13c provided so as to correspond to each of the plurality of laser light sources 11a to 11c parallelize the laser light L from the corresponding laser light sources.

The plurality of light diffusing elements 14a to 14c have light diffusing characteristics corresponding to the wavelength of the laser light L from the corresponding laser light sources 11a to 11c, and the diffusion angle of the laser light L of each wavelength is the light diffusing elements 14a to 14c. Matched by. After that, the laser light L of each wavelength is synthesized by the first optical guide body 51 and the second optical guide body 52, and is guided to the optical scanning device 21 via the relay optical system 18. The irradiation surface portion 19 of the optical scanning device 21 is arranged at a position based on the imaging position of the laser beam L from each of the plurality of light diffusing elements 14a to 14c. Then, the controller 22 controls the timing of emitting the laser light L from each laser light source in conjunction with the scanning control of the optical scanning device 21.

According to the above-mentioned illumination device 1, the desired element illumination region 41 of the illumination region 40 can be safely illuminated by the laser beams L having a plurality of wavelengths. Therefore, for example, it is possible to illuminate the illumination region 40 with full-color light by emitting laser light L having a red wavelength, a green wavelength, and a blue wavelength from the laser light sources 11a to 11c.

[Third Embodiment]
FIG. 10 is a conceptual diagram showing a schematic configuration of the lighting device 1 according to the third embodiment of the present invention. In the present embodiment, the same or similar elements as those in the second embodiment described above are designated by the same reference numerals, and detailed description thereof will be omitted. In addition, in order to facilitate illustration and understanding, the illustration of the laser beam L in the collimating optical systems 13a, 13b, 13c to the optical scanning device 21 is omitted in FIG.

In the present embodiment, only one light diffusing element 14 is provided, and the light diffusing element 14 is composed of a microlens array. The optical guide unit 50 is arranged so as to guide laser light L having different wavelengths from a plurality of laser light sources 11a to 11c to the light diffusing element 14.

Specifically, the first optical guide body 51 having a dichroic mirror is installed between one of the plurality of laser light sources, the first laser light source 11a in FIG. 10, and the light diffusing element 14. There is. Further, the second optical guide body 52 is located at a position where the laser light L from each of the other laser light sources, the second laser light source 11b and the third laser light source 11c in the example shown in FIG. 10, is guided to the first optical guide body 51. Have been placed. More specifically, the first optical guide body 51 is arranged between the first collimating optical system 13a and the light diffusing element 14. Further, the second optical guide body 52 is arranged at a position where the laser light L from each of the second collimating optical system 13b and the third collimating optical system 13c is guided to the first optical guide body 51. The first optical guide body 51 receives the laser light L from the first laser light source 11a and the laser light L traveling from the second laser light source 11b and the third laser light source 11c via the second optical guide body 52. It leads to the light diffusing element 14.

As described above, the optical guide unit 50 is a laser beam having different wavelengths after being emitted from the plurality of laser light sources 11a to 11c and passing through the plurality of beam expanders 12a to 12c and the plurality of collimating optical systems 13a to 13c. L is guided to the light diffusing element 14.

In the present embodiment, laser light L from a plurality of laser light sources 11a to 11c is synthesized before the light diffusing element 14. Then, the controller 22 controls the timing of emitting the laser light L from each laser light source in conjunction with the scanning control of the optical scanning device 21.

[Fourth Embodiment]
FIG. 11 is a conceptual diagram showing a schematic configuration of the lighting device 1 according to the fourth embodiment of the present invention. In the present embodiment, the same or similar elements as those in the third embodiment described above are designated by the same reference numerals, and detailed description thereof will be omitted. In addition, in FIG. 11, the illustration of the laser light L in the laser light sources 11a, 11b, 11c to the optical scanning device 21 is omitted in order to facilitate the illustration and understanding.

In this embodiment, only one beam expander 12 and one collimating optical system 13 are provided, and the optical guide unit 50 is provided in front of the beam expander 12. The first optical guide body 51 is arranged between the first laser light source 11a and the beam expander 12. The second optical guide body 52 is arranged at a position where the laser light L from each of the second laser light source 11b and the third laser light source 11c is guided to the first optical guide body 51. The first optical guide body 51 and the second optical guide body 52 synthesize laser light L from a plurality of laser light sources 11a to 11c in the stage prior to the beam expander 12. The combined laser light L is emitted from the first optical guide body 51 toward the beam expander 12.

In this way, the optical guide unit 50 emits laser light L having different wavelengths from the plurality of laser light sources 11a to 11c toward the beam expander 12 and the collimating optical system 13 and guides the laser light L to the light diffusing element 14. .. The collimating optical system 13 parallelizes laser light L having different wavelengths from a plurality of laser light sources 11a to 11c. Then, the controller 22 controls the timing of emitting the laser light L from each laser light source in conjunction with the scanning control of the optical scanning device 21.

[Fifth Embodiment]
FIG. 12 is a conceptual diagram showing a schematic configuration of the lighting device 1 according to the fifth embodiment of the present invention. In the present embodiment, the same or similar elements as those in the above-described first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. In order to facilitate illustration and understanding, FIG. 12 shows only the laser light L from the laser light source 11 to the collimating optical system 13, and the illustration of the laser light L in other parts is omitted.

In the present embodiment, the relay optical system 18 is omitted, and the light diffusing element 14 is provided between the optical scanning device 21 and the illumination region 40. The optical scanning device 21 changes the traveling direction of the laser light L traveling from the laser light source 11 via the beam expander 12 and the collimating optical system 13, and the light diffusing element 14 transmits the laser light L from the optical scanning device 21. Spread.

The laser beam L from the laser light source 11 is applied to the optical scanning device 21 after the beam diameter is expanded by the beam expander 12 and the collimating optical system 13 and adjusted to parallel light. Then, the optical scanning device 21 scans the laser light L that has passed through the light diffusing element 14 in the illumination region 40, and guides the laser light L to the element illumination region 41 that constitutes a part of the illumination region 40.

[Sixth Embodiment]
FIG. 13 is a conceptual diagram showing a schematic configuration of the lighting device 1 according to the sixth embodiment of the present invention. In the present embodiment, the same or similar elements as those in the fifth embodiment described above are designated by the same reference numerals, and detailed description thereof will be omitted. For ease of illustration and understanding, FIG. 13 illustrates only the laser light L from the laser light source 11 to the collimating optical system 13, and the illustration of the laser light L in other parts is omitted.

In the present embodiment, the laser light L emitted from the laser light source 11 and whose traveling direction is changed by the light scanning device 21 includes a plurality of types of light components having different wavelengths from each other. A spectroscopic unit 60 is provided between the optical scanning device 21 and the light diffusing element 14. The laser beam L from the optical scanning device 21 enters the light diffusing element 14 via the spectroscopic unit 60. The spectroscopic unit 60 disperses the laser light L incident on the spectroscopic unit 60 from the optical scanning device 21, separates the laser light L into a plurality of light components having different wavelengths, and diffuses the plurality of light components. It emits light toward the element 14.

The spectroscopic unit 60 shown in FIG. 13 includes a first spectroscopic guide body 61 and a second spectroscopic guide body 62. The first spectroscopic guide body 61 has a dichroic mirror that transmits light components in the first wavelength range and guides them to the light diffusing element 14 and reflects light components in other wavelength ranges. The second spectroscopic guide body 62 guides the light components in other wavelength regions reflected by the dichroic mirror of the first spectroscopic guide body 61 to the light diffusing element 14. Light components having different wavelengths guided by the first spectroscopic guide body 61 and the second spectroscopic guide body 62 are guided to different parts of the light diffusing element 14, and are incident on the corresponding light diffusing element 14 composed of, for example, a hologram. To do. Then, each light component is diffused by the corresponding light diffusing element 14 to illuminate the desired element illumination region 41 in the illumination region 40.

For example, when the light component in the red wavelength region, the light component in the green wavelength region, and the light component in the blue wavelength region are included in the laser light L from the laser light source 11, the laser light L incident on the spectroscopic unit 60 is in each wavelength region. It is separated into the light components of. Then, the light component in the red wavelength region is guided by the spectroscopic unit 60 so as to be incident on the light diffusing element 14 optimized for the light component in the red wavelength region. Similarly, the light component in the green wavelength region and the light component in the blue wavelength region are also guided by the spectroscopic unit 60 so as to be incident on the light diffusing element 14 optimized for each. Also in this embodiment, the controller 22 controls the timing of emitting the laser light L from each laser light source in conjunction with the scanning control of the optical scanning device 21.

<Other variants>
The present invention is not limited to the above-described embodiments and modifications, and other modifications may be added.

For example, one or more elements of the beam expander 12, the collimating optical system 13, and the relay optical system 18 may be omitted, and even for the lighting device 1 that does not include a part of the elements shown in FIG. , The present invention is effectively applicable. For example, when the relay optical system 18 is not installed, the irradiation surface portion of the optical scanning device 21 is located in the immediate vicinity of the light diffusing element 14, for example, at a position away from the light diffusing element 14 by the focal length of the light diffusing element 14 or near the position. 19 may be arranged and the illumination area 40 may be illuminated by the laser beam L. Further, in addition to the relay optical system 18, a condenser lens may be added on the upstream side of the optical scanning device 21, that is, on the laser light source side. Further, a condenser lens may be provided on the downstream side of the optical scanning device 21, that is, on the side opposite to the laser light source side.

The application target of the above-mentioned lighting device 1 is not particularly limited, and for example, the lighting device 1 may be mounted on a vehicle such as a vehicle or an aircraft, a vehicle such as a train, a ship, or a diving object, or another moving body. , The lighting device 1 may be installed in a specific place.

Aspects of the present invention are not limited to the individual embodiments described above, but also include various modifications that can be conceived by those skilled in the art, and the effects of the present invention are not limited to the contents described above. That is, various additions, changes and partial deletions can be made without departing from the conceptual idea and purpose of the present invention derived from the contents defined in the claims and their equivalents.

1 Illumination device 11 Laser light source 12 Beam expander 13 Collimating optical system 14 Light diffusion element 15 Unit diffusion element 16 First relay lens 17 Second relay lens 18 Relay optical system 19 Irradiation surface unit 20 Scanning drive unit 21 Optical scanning device 22 Controller 25 Light emission timing control unit 26 Optical scanning control unit 31 Virtual microlens array 40 Illumination area 41 Element illumination area 45 Folded mirror 48 Optical fiber 50 Optical guide unit 51 First optical guide body 52 Second optical guide body 60 Spectro unit 61 First spectroscopic guide Body 62 Second spectral guide body L Laser light

Claims (17)

A coherent light source that emits coherent light,
A light diffusing element that diffuses the coherent light from the coherent light source,
An optical scanning device that scans the coherent light from the light diffusing element in the illumination region, and an optical scanning device that guides the coherent light to an element illumination region that constitutes a part of the illumination region.
With
A relay optical system is not provided between the light diffusing element and the optical scanning device,
The optical scanning device is arranged at a position based on an imaging position determined according to the optical performance of the light diffusing element .
The optical scanning device includes an irradiation surface portion that is irradiated with the coherent light from the light diffusing element to change the optical path of the coherent light, and a scanning drive unit that adjusts the arrangement of the irradiation surface portion.
A lighting device in which the diffusion angle of the coherent light by the light diffusion element is smaller than the angle of the element illumination region with respect to the irradiation surface portion . The light diffusing element has a plurality of unit diffusing elements and has a plurality of unit diffusing elements.
The lighting device according to claim 1, wherein the optical scanning device is arranged at a position based on an imaging position determined according to the optical performance of the plurality of unit diffusion elements. The lighting device according to claim 1 or 2, further comprising a controller that controls the timing of incident of the coherent light on the light diffusing element or the lighting timing of the lighting region. The lighting device according to claim 1 or 2, further comprising a timing control unit that controls the emission timing of the coherent light in response to scanning of the coherent light by the optical scanning device. The lighting device according to any one of claims 1 to 4, wherein the diffusion angle of the coherent light by the light diffusing element is larger than 0.05 ° and smaller than 2 °. It said angle of said element illumination region irradiated surface as a reference, the lighting device according to less than 5 ° 5. greater than 0.1 ° of the optical scanning device. The lighting device according to any one of claims 1 to 6 , wherein the light diffusing element is a hologram. The lighting device according to any one of claims 1 to 6 , wherein the light diffusing element is a microlens array. The lighting device according to any one of claims 1 to 8 , further comprising a beam expander arranged between the coherent light source and the light diffusing element to expand the diameter of the coherent light from the coherent light source. The illuminating device according to claim 9 , further comprising a collimating optical system arranged between the beam expander and the light diffusing element to parallelize the coherent light from the beam expander. A plurality of the coherent light sources that emit coherent light having different wavelengths are provided.
A plurality of the light diffusing elements provided so as to correspond to each of the plurality of coherent light sources, and a plurality of the light diffusing elements for diffusing the coherent light from the corresponding coherent light source are provided.
The lighting device according to claim 7 , further comprising an optical guide unit for guiding coherent light having different wavelengths from the plurality of light diffusing elements to the optical scanning device. The optical guide unit is
A first optical guide body installed between the light diffusing element of one of the plurality of light diffusing elements and the optical scanning device, and
A second optical guide body that guides the coherent light from another light diffusing element among the plurality of light diffusing elements to the first optical guide body is included.
The lighting device according to claim 11 , wherein the first optical guide body guides the coherent light from the one light diffusing element and the coherent light from the other light diffusing element to the optical scanning device. A plurality of the coherent light sources that emit the coherent light having different wavelengths from each other are provided.
The lighting apparatus according to claim 8 , further comprising an optical guide unit for guiding the coherent light having different wavelengths from the plurality of coherent light sources to the light diffusing element. The optical guide unit is
A first optical guide body installed between the coherent light source of one of the plurality of coherent light sources and the light diffusing element, and
A second optical guide body that guides the coherent light from the other coherent light source among the plurality of coherent light sources to the first optical guide body is included.
The lighting device according to claim 13 , wherein the first optical guide body guides the coherent light from the one coherent light source and the coherent light from the other coherent light source to the light diffusing element. A plurality of collimating optical systems provided so as to correspond to each of the plurality of coherent light sources, further comprising a plurality of collimating optical systems for parallelizing the coherent light from the corresponding coherent light source.
The 13 or 14 claim, wherein the optical guide unit guides the coherent light having different wavelengths after being emitted from the plurality of coherent light sources and passing through the plurality of collimating optical systems to the light diffusing element. Lighting equipment. Further provided with a collimating optical system for parallelizing the coherent light having different wavelengths.
The lighting device according to claim 13 or 14 , wherein the optical guide unit emits the coherent light having different wavelengths from the plurality of coherent light sources toward the collimating optical system and guides the coherent light to the light diffusing element. .. Further equipped with a beam expander that expands the diameter of the coherent light,
The lighting device according to claim 16 , wherein the optical guide unit guides the coherent light having different wavelengths from the plurality of coherent light sources to the light diffusing element via the beam expander and the collimating optical system. ..

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